WASHINGTON (CNN) - Pennsylvania State Treasurer Bob Casey, Jr., continues to lead incumbent GOP Sen. Rick Santorum in Pennsylvania's U.S. Senate race, according to the latest poll conducted by Temple University and the Philadelphia Inquirer.

Casey, the Democratic nominee and son of the late former Gov. Bob Casey, Sr., leads Santorum 49 percent to 39 percent, while 3 percent favored Green Party candidate Carl Romanelli. Eight percent of respondents said they were undecided.

The poll surveyed 666 likely voters from September 14-20 and has a margin of error of plus or minus 3.8 percent. Santorum has trailed Casey in several independent polls taken this year.

WASHINGTON (CNN) - Democratic Rep. Sherrod Brown is ahead in his bid to unseat Sen. Mike DeWine, R-Ohio, according to a new Columbus Dispatch poll. Brown leads DeWine 47 percent to 42 percent, a slightly tighter race than in July, when a Dispatch Poll had Brown with an eight-point lead. The poll, released Sunday, surveyed 1,791 registered voters between September 9 and 22 and has a margin of error of plus or minus 2.2 percent.

WASHINGTON (CNN) - Republican Tom Kean, Jr., leads Democratic Sen. Robert Menendez 44 percent to 38 percent in New Jersey's U.S. Senate race, according a poll released Sunday. The poll, conducted by Monmouth University and sponsored by Gannett New Jersey, surveyed 391 likely voters and has a margin of error of plus or minus 5 percent.

A Quinnipiac poll released earlier this month also showed Kean with a slight lead over Menendez, who took office in January when Democratic Sen. Jon Corzine resigned to become governor. Kean is the son of former GOP Gov. Tom Kean, Sr., who also co-chaired the 9/11 Commission.